1. Field of the Invention
The invention is directed to the carbonylation of halo-hydrocarbons to produce aromatic, aromatic acetic and olefinic acids, esters, thioesters, amides, and the like.
2. Related Art
It is known to carbonylate halo-hydrocarbons such as benzyl chloride by reaction with carbon monoxide and an alcohol at 100.degree. C. or below and at atmospheric pressures in the presence of an amine and a catalytic amount of a palladium catalyst to form esters.
An article entitled "Palladium-Catalyzed Carboalkoxylation of Aryl, Benzyl, and Vinylic Halides" by A. Schoenberg et al. appearing in The Journal of Organic Chemistry, Vol. 39, page 3318, (1974) discloses a process whereby aryl and vinylic bromides and iodides and benzyl chloride are each reacted with carbon monoxide and an alcohol at 100.degree. C. or below and at atmospheric pressures in the presence of a tertiary amine and a catalytic amount of a palladiumtriphenylphosphine complex to form esters. The tertiary amines disclosed in tributyl amine. There is no teaching or disclosure relative to use of branched tertiary aliphatic amines or excess phosphine in the process.
U.S. Pat. No. 3,116,306 discloses a process for preparing carboxylated organic compounds by reacting (1) an organic compound represented by the general formula R.sub.n Z in which R is an organic compound having at least one aliphatic radical or cycloaliphatic radical, Z is SO.sub.4, X, X.sub.2 or R'SO.sub.3, X being a halogen and R' is alkyl, alkenyl, cycloalkyl, aryl or aralkyl, where n is 1, Z is X, X.sub.2 or R'SO.sub.3, and when n is 2, Z is SO.sub.4, the Z substituent being attached to an aliphatic or cycloaliphatic primary or secondary carbon atom; (2) carbon monoxide; (3) a salt of a metal hydrocarbonyl of the group consisting of cobalt hydrotetracarbonyl and iron dihydrotetracarbonyl and (4) a material of the group consisting of water, alcohols, phenols, mercaptans, ammonia, hydrazine, primary organo-nitrogen bases and secondary organo-nitrogen bases.
The above cited patent discloses that tertiary amines such as dicyclohexylethylamine have been found to be of general use in the process of the invention.
U.S. Pat. No. 3,708,529 teaches a process for synthesizing phenylacetic acid by carbonylation of benzyl chloride. The process discloses reacting benzyl chloride and carbon monoxide under atmospheric pressure at temperatures from 20.degree. C. to 80.degree. C. in a water-methanol medium containing up to 35% water, using a catalyst mixture consisting of a cobalt salt, an iron-manganese alloy and a sulfurated promoting agent.
There is no description of utilizing a hindered amine base in conjunction with a palladium catalyst in any of the above references or the use of an excess of phosphine in the process.
U.S. Pat. No. 4,480,121 discloses the palladium catalyzed carbonylation of 2-halo-1-alkenes, and the use of several amine compounds as bases which are within the description of the hindered amine base utilizing the instant invention.
In an article entitled "Carboalkoxylation of Aryl and Benzyl Halides Catalyzed by Dichlorobis(triphenylphosphine)palladium (II)" by John K. Stille et al. appearing in the Journal of Organic Chemistry, Vol. 40, pages 532 (1975) there is disclosed a process for the carbonylation of organic halides using palladium catalysts. The article mentions the severe reaction conditions required using palladium catalysts (200 psi and a reaction time of greater than or equal to 20 hrs.). Also mentioned is the use of tertiary amine bases in the process. The amine compounds mentioned in the article are triethylamine, 2,6 lutidine, and 1,8-bis(dimethylamino)napthalene.
In a paper entitled "Carboxymethylation of Organic Halides by Palladium Complexes under Mild Conditions" by Masanobu Hidai et al. appearing in the Bulletin of the Chemical Society of Japan, Vol. 48 (7), pages 2075-2077 (1975) there is disclosed the carboxymethylation of various organic halides under what are described as very mild conditions. The article discloses that the carbonylation of organic halides by transition metal complexes have been reported but that the reactions required high temperatures and pressures with low yields of the carbonylated products. In the article there is described a process using palladium complexes and, as an amine source, diethyl amine. There is further described the use of other amines such as, for instance, dicyclohexyl amine. There is no disclosure or suggestion of using a tertiary amine or, more importantly, a hindered tertiary amine having, for example, branched alkyl groups thereon.
In none of the above references is there taught, suggested or shown the combination of a hindered tertiary amine base in combination with a palladium catalyst and an excess of phosphine.